I like the idea of using verbs rather than nouns; they are more describing while being open enough (see Chuck’s examples here) and there are fewer (hence more to the point) possibilities.

However, I’m still a big fan of folksonomy; it’s much more flexible and quicker than taxonomy, especially in an organization’s environment where you’d have to go to the admin to get a new tag created if the one you need right now does not exist.

But I believe that Chuck’s idea (or rather that of his team), can be used in a sort of « directed folksonomy »; you could leave your users decide on their tags, but give them the recommendation to use verbs.

I admit that it would be quite difficult to keep an eye on all the tags created to check if they’re indeed verbs, but I’m sure that some sort of technical solution can be found to make it easier …